Successful Observation of Intrinsic Piezoelectric Property of Widely Used Piezoelectric Material -A 60-year-old problem has been solved, paving the way to the development of novel lead-free piezoelectric materials- (Press Release)
- Release Date
- 16 Jul, 2014
- BL13XU (Surface and Interface Structures)
Tokyo Institute of Technology
National Institute for Materials Science (NIMS)
Nagoya University
|
A research group fabricated single-crystalline films of lead zirconate titanate [Pb(Zr,Ti)O3 or PZT], one of the most widely used piezoelectric materials, and successfully determined the conversion coefficient between the electric and mechanical energies by direct observation of the films. The group was led by Hiroshi Funakubo (professor) of the Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology; Osami Sakata (Synchrotron X-ray Station Director) of the Research Network and Facility Services Division, NIMS, and Tomoaki Yamada (associate professor) of the Graduate School of Engineering, Nagoya University [who is supported by the Precursory Research for Embryonic Science and Technology (PRESTO) program, Japan Science and Technology Agency]. Piezoelectric materials *1 change their structures upon receiving electrical voltages.On the basis of this property, they are used in ignitors in stove burners, mist generators in humidifiers, and power sources of micro-electromechanical systems (MEMS)*2 used in inkjet and three-dimensional printers. PZT has been practically applied for 60 years; nevertheless, the conversion coefficient between the electric and mechanical energies, one of the most basic piezoelectric properties, has remained unclear because the crystalline and ultrafine structures of PZT vary in a complicated manner upon the receipt of electrical signals. The researchers of the group directly measured the strain of the crystal lattice of their first-ever successfully fabricated a PZT single-crystal film. This strain was induced by the high-speed application of electrical voltages and measured using synchrotron X-ray diffraction at SPring-8, a large synchrotron radiation facility*3. As a result, they succeeded in observing the distortion of the crystal lattice in a very short time of ≤20 ns*4. The conversion coefficient between the electric and mechanical energies of the PZT single crystal was also successfully determined for the first time. The achievements of this research were published online in Applied Physics Letters, a prestigious scientific journal in the field of applied physics, on 9 July 2014. Publication： |
《Figures》
In the constructed system, a diffraction intensity is detected from an area of several micrometers on a top electrode irradiated by high-brilliance X-rays under repeated pulse voltages with a fixed height and a 200 ns width.Electric polarization is simultaneously measured through the same top electrode.
The change in the diffraction angle of the crystal indicates the strain of the crystal; the smaller the angle, the more the crystal is stretched. With increasing applied voltage, the changes in the amount of charge and crystal strain increase.
The conversion coefficient between the electrical and mechanical energies was successfully determined for the first time in the world from the slope of this graph.
《Glossary》
*1 Piezoelectric thin film
A crystal exhibits dielectric polarization when an external pressure is applied, which is referred to as the piezoelectric effect. The crystal is distorted when an electric field is applied, which is referred to as the inverse piezoelectric effect. Crystals that exhibit these behaviors are called piezoelectric materials, and those in the form of thin films are called piezoelectric thin films.
*2 Micro-electromechanical systems (MEMS)
Devices in which mechanical components, sensors, actuators, and electric circuits are integrated in one silicon, glass, or organic substrate.
*3 SPring-8, a large synchrotron radiation facility
SPring-8 (Harima Science Park, Hyogo, Japan) is a synchrotron radiation facility that provides the world's highest brilliance radiation. It’s owned by Riken and run by JASRI. The name 'SPring-8' is from “Super Photon ring-8 GeV”. Synchrotron radiation is a electromagnetic wave radiated when charged particles are forced to bend in magnetic fields. Synchrotron radiation from SPring-8 is widely used for the studies of nano-technology, bio-technology and industrial purposes.
*4 Nanosecond
One nanosecond is one-billionth of a second.
|
For more information, please contact: E-mail: 
|
- Previous Article
- Discovery of High-Pressure Minerals in HED Meteorites（Press Release）
- Current article
- Successful Observation of Intrinsic Piezoelectric Property of Widely Used Piezoelectric Material -A 60-year-old problem has been solved, paving the way to the development of novel lead-free piezoelectric materials- (Press Release)